1. Field of the Invention
The present invention relates to an image forming system, and more particularly, to an image forming apparatus and peripheral apparatuses thereof, each having a power saving function, such as a digital multi-function system and a facsimile communication system.
2. Description of the Related Art
An image forming system that, when it is turned on but left not operated for a predetermined time period, automatically stops supplying electric power to a high-power consuming component or turns off the entire system is publicly known in the related art. Such an image forming system moves, when it remains not operated for a predetermined time period after a previous operation, to a power saving mode where the temperature of a fixing unit is lowered and/or the operation of units other than a control unit is suspended, for example. The image forming system returns to a normal operation mode by a certain trigger mechanism activated in response to a request to operate.
For example, an image forming apparatus disclosed in the Japanese laid-open patent application No. 2000-035732 can turn off a printer control unit while being set at a power saving mode, and resume operating in response to a reversion trigger signal sent by a remote host computer through a communication channel provided for a logging function that enables the image forming apparatus to exchange data with the remote host computer. In the case of this image forming apparatus, however, the remote host computer has to send the reversion trigger signal to output an image every time. The image forming apparatus becomes complicated since the logging function must be implemented in the image forming apparatus.
The Japanese laid-open patent application No. 2001-018486 discloses an image forming system that reduces the standby power consumption of a control unit by controlling the power supply with a printer controller. Such an image forming system, however, cannot reduce its power consumption sufficiently because the printer controller itself does not move to the power saving mode.
In the case of the image forming apparatus and/or the image forming system according to the related art, a specific control unit monitors the reversion trigger signal and sets the entire apparatus and/or system at the normal operation mode in response to the detection of the reversion trigger signal. Because a portion that does not necessarily need to be turned on is turned on, the power consumption of the apparatus and/or system is not reduced enough.